Weekly gardening blog giving tips, ideas and tutorials.

When To Prune Lilac Bushes

Lilacs (Syringa spp.) have to be one of the best smelling flowers of spring. They have such an intense aroma.

In order to make sure you enjoy your lilac flowers every year, they will need to be periodically pruned. Lilacs, like many flowering shrubs flower on new growth.

So if you haven’t pruned your lilac in a while, and you have been getting fewer and fewer flowers every year – you need to prune.

Most lilacs don’t need to be pruned until they have matured and reached six or seven feet (2 to 2.25 m) tall, and there are two ways you can prune them.

1. In the spring right after they have finished flowering since this will allow new shoots plenty of time to grow and develop buds for next season.

2. Or if your plant is really old and has stopped flowering, prune in late winter, early spring while the shrub is still dormant. You want to do this because it’s easier to see the old wood and new wood.

Take some loppers or really sharp pruners and go through and thin out all the old wood stems all the way down to the base of the plant. This will thin your plant out and allow new wood to grow, and you’ll have many more flowers as a result.

Pruning lilacs is easy and fast and there is no better way to ensure regular flower production than cutting them back every year or two.

It’s also better for their health, because when you open up a lilac plant by thinning it out, you allow better air circulation and less powdery mildew and other diseases will occur.

Lastly, don’t worry if you prune too much off. Lilacs are tough plants and they will come back even better the next season.